* This fix drastically improves performance since it eliminates
an unnecessary update of the workflow execution object when
processing "on_action_complete" operation. W/o this fix
all such transactions would have to compete for the workflow
executions table that causes lots of DB deadlocks (on MySQL)
and transaction retries. In some cases the number of retries
even exceeds the limit (currently hardcoded 50) and such tasks
can be fixed only with the integrity checker over time.
See the code comment in the "dispatcher.py" module that explains
why this specific change eliminates the update of the workflow
execution object.
* Style changes in api.py and aciton_execution_checker.py
Closes-Bug: #1790079
Change-Id: I08cb561e252d31e35fcfb61984d87a7bfc387a4d